Studio Tech’s Corner: Ampex Advanced Cookware

Thursday, February 7th, 2013

Since before my time, the Ampex 300-3 has been sitting to the right of the Otari, dusty and silent. And every once in a long while, Bob would stare at in mournfully and say. “Someday we’ll get that thing working, and it will be the coolest ever.”

Well someday has finally come, and it is in fact the coolest ever. Just look at those giant knobs.

We got the 300-3 as part of the deal to get the Ampex MM1100 16-track machine that is our primary tracking deck. Bob recapped and rebuilt most of the audio electronics (thanks!) a while back, so what was left to do was testing, troubleshooting, calibrating, and general de-kinking. It had a few kinks

But Ephriam was recording with Iska Daaf in the studio, so first I had to move the deck and all my gear into the kitchen. Fortunately no one was working over the holidays (besides Ephriam, Iska Daaf, and I).

And then I sort of just fixed problems as they came up. For about 5 days, two new things would pop up whenever I fixed something, then it slowly started settle down. I can’t remember them all, tubes burning out, pots and trimmers needing lubrication, solder needing retouching, corroded card edges. On one memorable occasion all the 12ax7s in one module stopped heating because because the connector from the negative rail of the rectifier was not pinching the card edge hard enough (so the circuit was open). Exciting stuff.

The reason I was finally getting the machine working was Karl Blau wanted to use it , but by time he arrived, only three tracks were working. All four had been sort-of working, but at 5pm the night before, Channel 1 had stopped reproducing, recording, and erasing (all the things it is supposed to do). Karl seems unperturbed and did a few days with just three tracks.

As always the real problem is the elusive studio Gremlin

Then I had three days to figure out the other channel before he came back. Day One I redid the janky looking cable going from the repro head to the audio electronics, and that fixed the repro problem, but not the erase and record. A fader on the board broke overnight so I spent Day 2 fixing that. Day 3, I took the Track 1 module apart for the billionth time and started taking voltages and comparing it to a working unit, but then I had to leave to pick up a henhouse, and I didn’t end of coming back until 10pm. I was just gonna call it a night, but for some reason I sat back down and started testing voltages again, and an hour and a half later I had found a single resistor, hiding under some poly caps, with a snapped lead. This particular resistor coupled power to the plates of all the tubes on the record card and had caused all my problems.

So the 4-track works. Karl recorded his album on it. FOR SERIOUS COME USE IT. We’ll do an album in a day like the fucking Beatles. The early Beatles.

3 responses to “Studio Tech’s Corner: Ampex Advanced Cookware”

I am just old enough to have Bakelite knob lust. I’m a pragmatist, not a purist. I’ve been recording and mixing digitally for years, But I love a vibe, a flow, a sound, and a story to go with the song. I respect the work you did; thank you. I hope this deck records hundreds of artists for K!